The present invention relates generally to a method and apparatus for decomposing sulfuric acid into SO2, O2 and H2O.
The production of hydrogen as an alternative fuel can be accomplished through several means, including high temperature thermochemical cycles. These cycles are essentially a coupled set of chemical reactions that result in the decomposition of water to hydrogen and oxygen at much lower temperature than direct dissociation of water. The current focus of research in this area is on the sulfur cycles, which require the decomposition of sulfuric acid (H2SO4) to form SO2. Sulfuric acid is regenerated in other parts of the cycle. The SO2 produced from H2SO4 is used in subsequent chemical or electrochemical steps to produce H2. The conversion of H2SO4 to SO2 can be accomplished at very high temperature (>1000° C.), or at lower temperatures in the presence of a catalyst (˜750-900° C.). The combination of concentrated sulfuric acid and high temperatures results in a highly corrosive environment. At these high temperatures required for the reaction, connections, seals and gaskets for process components are susceptible to leaks and failure. Additionally, for the process to be economical, heat input into the process to boil, superheat, and decompose the acid must be recovered and reused. For use on a large-scale, for example to produce hydrogen as an alternative energy source to fossil fuels, the sulfuric acid decomposer must be scaleable, efficient, reliable, and cost effective.
Against this background, the present invention was developed.